1. Field of the Invention
The present invention relates to a connecting structure for fixedly connecting a liquid crystal display and a flexible flat cable with a resin.
2. Description of the Prior Art
FIGS. 4, 5 and 6 are drawings of assistance in explaining a conventional connecting structure for connecting a liquid crystal display and a flexible flat cable, in which FIG. 4 is a plan view of a flat flexible cable and a liquid crystal display before connection, FIG. 5 is an illustration of assistance in explaining the steps of a connecting process for connecting a liquid crystal display and a flexible flat cable, and FIG. 6 is an illustration showing a liquid crystal display and a flexible flat cable fixedly connected together.
Referring to FIGS. 4, 5 and 6, a liquid crystal display 1 comprises an upper glass substrate 2, a lower glass substrate 3, a liquid crystal, not shown, between the glass substrates 2 and 3, and a polarizing plate 4. Transparent electrodes formed of ITO films or the like are formed over the respective inside surfaces of the glass substrates 2 and 3 in patterns corresponding to display patterns 5. Electrode terminals 6 for electrically connecting the liquid crystal display 1 to an external device extend over the surface of one end of the lower glass substrate 3. The electrode terminals 6 are formed of the same material as that forming the transparent electrodes formed on the glass substrates 2 and 3, and are connected to the transparent electrodes, respectively. Silver layers 7 are formed respectively over the electrode terminals 6 by applying a silver paste to the electrode terminals 6 through a printing process. The silver layers 7 are coated respectively with solder layers 8. A flexible flat cable 9 (hereinafter referred to simply as "cable") comprises a base film 10 such as a polyimide film, connecting electrodes 11 formed over the base film 10 by etching a thin copper film, and an insulating protective layer 12. Portions of the connecting electrodes 11 extending in the free end of the base film 10 are exposed and are coated respectively with solder layers 8.
In connecting the liquid crystal display 1 and the cable 9, the free end of the cable 9 is placed on the lower glass substrate 3 with the connecting electrodes 11 positioned respectively on the corresponding electrode terminals 6 of the liquid crystal display 1, heat, for example, heat of 25.degree. C., and pressure is applied to the solder layers 8 for a predetermined time, for example, three seconds, by a heating member 17 to cause the corresponding solder layers 8 to fuse together so that the electrode terminals 6 and the corresponding connecting electrodes 11 are soldered, and then, an UV (ultraviolet) setting resin 13 is applied to the upper surface of the cable 9, the end surface of the upper glass substrate 2, the lower surface of the cable 9 and the end surface of the lower glass substrate 3 as shown in FIG. 6 to bond firmly together the liquid crystal display 1 and the cable 9.
In securing the upper and lower surfaces of the cable 9 respectively to the end surfaces of the upper glass substrate 2 and the lower glass substrate 3 with the resin 13, the resin 13 is applied to one surface of the cable 9, the resin 13 applied to one surface of the cable is hardened in a furnace, the resin 13 is applied to the other surface of the cable 9 after the resin 13 applied to the former surface of the cable 9 has been hardened, and then the resin 13 applied to the latter surface of the cable 9 is hardened in the furnace, which requires much time and is not satisfactory in respect of efficiency of production.